NUX brand already announced B-2 guitar wireless in 2017, and now they have several wireless products in this category.
NUX品牌從2017發布B-2吉他無線系統,至今有許多無線產品。
Recently NUX announced B-8, the ID design is quite unique, looks quite professional, and offers some interesting functions.
最近NUX發表了B-8,外觀工業設計相當獨特,看起相當專業且提供了一些有趣的功能。
B-8 comes with a bodypack TX, and pedal RX. Let's check the TX first.
B-8帶有腰掛式TX(發射端),以及效果器踏板型RX(接收端)。 讓我們先來看下TX的部分。
You can clip the TX on the guitar strap, and connect the additional cable to the guitar output jack.
TX可以讓你夾在吉他背帶上,並使用原廠附的導線接到吉他輸出接口上。
Most professional-stage wireless systems use the same design~ additional cable. Cause the stage wireless requires a long transmission distance, it means the TX has to run a higher RF signal. In this situation, the compact wireless design like B-5RC (directly into the guitar jack) will have RF high-frequency noise issues with active pickups or preamps.
So the TX uses the additional cable can keep enough distance from pickups/preamps to avoid the RF noise issue.
TX's power button also offers the mute function, hold it for a while it will mute, and then you can change the guitar. Short press again, and it will start to work again. Long press to turn ON/OFF.
The TX offers a unique "CABLE TONE" function, if you engage it, the built-in RC circuit can adapt to the pickup's impedance to simulate the "real cable capacitor effect". It sounds pretty natural.
Note: If you use active pickups, the cable tone won't be obvious due to the low impedance.
Let's check the RX. The RX can be powered by "7V to 12V DC, 500mA min, negative tip power supplies(Receiver)", I think most guitarists will feed 9V negative tip power.
讓我們來看下RX,RX可以使用7V~12V DC 外正內負 直流電500mA9來供電,我想多數吉他手都會使用9V 外正內負來供電。
So I checked the power consumption with 2 situations:
TX & RX work with the wireless operation.
TX puts on RX for charging. (The power consumption of charging is various, it depends on TX's battery status. Here I guess at least 320mA is required.)
For the RX, the special part is the routing system design. It offers SEND/RETURN to let you connect the pedals from the beginning to the end and back to the RX to use RETURN OUTPUT to connect with the amplifier. The RX even offers XLR balanced out to the PA system.
The RX can be a pedal tuner or a volume boost!! You can set up the function and footswitch on the RX.
接收端還可以作為『踏板調音器』或者『音量推子』!! 你可以在RX本體上設置這些以及踩釘功能。
Performance Testing and Comparison | 性能測試與對比
System Latency | 系統延遲
The working principle of B-8: 2 frequency points for wireless transmission with 1 MHz bandwidth. The lowest latency 2.5ms sends the transmission signal 2 times. The longest latency 8.7ms sends the transmission signal 12 times.
According to B-8's 1 MHz bandwidth, for real environment testing, B-8 can run longer distances without RF interference than Shure GLXD6.
實測真實環境中,由於B-8使用 1 MHz 帶寬工作,B-8可以移動得更遠且不受RF射頻干擾。
Note: 2.4GHz wireless is a kind of WAVE. According to what we learned before: v = f λ , λ is the wavelength.
Bandwidth is related to the wavelength, and in digital communication systems, it also means the data size.
註記: 2.4 GHz 無線也是一種波。 根據以前所學: v = f λ , λ 為波長。
帶寬與波長相關,在數位通信系統裡,帶寬也意味著數據封包大小。
Note: Why is the bandwidth smaller can against interference better? You can think 4MHz is like a truck, 2MHz is like a car, 1MHz is like a motorcycle. While they run on the road, the motorcycle can avoid others easily.
Small is always better? It's also related to the compression algorithm, how to keep the unzipped sound high quality is the challenge. For example, Xvive U2 uses 4MHz, so it drops the signal more easily than others. Shure GLXD6 uses 2MHz, it's much more stable than most competitors, and their compression algorithm also keeps the unzipped sound with good quality. NUX B-8 uses 1MHz and also keeps the unzipped sound great quality. It means B-8's compression algorithm is the most premium.
Using 1K frequency to test the system noise, Shure GLXD6's system noise is around -140 dB, and NUX B-8's system noise is around -150 dB.
Note: A great audio system can accept the system noise under -120 dB. (around 10uV) The guitar amplifier's system noise is much louder than the 2 wireless systems.
Shure enhanced the signal a little bit. NUX B-8 is more flat.
Shure的信號有些微放大。 B-8頻響更為平坦。
Frequency vs Distortion | 頻率對應失真特性
Shure has more distortion according to the whole frequency.
But these 2 systems' distortions are quite small already.
Shure明顯在各個頻率都比B-8容易失真。
但這兩個系統的失真都處於極小的狀態了。
Headroom | 動態餘量
Shure GLXD6's headroom is wider than NUX B-8.
Shure GLXD6 的動態餘量比NUX B-8還寬一點。
Note: Headroom means the acceptable signal range till overdrive. You can check the above, B-8 runs over 1 at around 2.034 Vrms, and GLXD6 runs over 1 at around 2.7 Vrms.
2.034 Vrms x ±(√2)= ± 2.8775 V ,基本上吉他跟貝斯都可以使用B-8,但主動式貝斯就要注意不要將所有信號開到最大來使用。 (主動式貝斯信號範圍約 ± 3V)
註:被動式吉他信號範圍約 ± 1V
主動式吉他信號範圍約 ± 2V
主動式貝斯信號範圍約 ± 3V
Let's talk about 2.4GHz | 淺談2.4GHz
Nowadays, there are many 5.8GHz wireless products, even Shure GLXD6 update to GLXD6+ to run both 2.4GHz & 5.8GHz. Why did NUX B-8 choose 2.4GHz?
There are 2 main reasons:
1. 5.8GHz is not allowed in Japan.
2. If you can make 2.4GHz stable and reliable with auto-hopping technology. 2.4GHz has better diffraction than 5.8GHz. It will be more suitable for outdoor application, especially on the stage.
Shure slashes 2.4GHz as 19 frequency bands. Taking off 3 strong WiFi interference bands and the auto scan & sync band, there are 15 bands for wireless transmission.
(專業級2.4GHz私有協議帶寬通常為2MHz(數位壓縮差的會使用到4MHz帶寬),加上Ramp Up / Down的 1 MHz,需要4MHz的頻寬。)
(83-8)/ 4 = 19個頻段 (最前面的4MHz跟最後面的4MHz皆須捨棄)
The bandwidth is related to frequency band slash and packet size. According to the above, you can realize Shure's compression algorithm is quite professional already. It compresses the packet small enough. (2MHz) The most difficult part of wireless is: How to compress the packet small enough and unzip it to keep high-quality sound without distortion.
So the 2.4GHz wireless system is a balance of "Signal Strength", "Transmission Distance", "Pickup Noise", and also the balance of "Digital Compression Algorithm to minimize the Bandwidth", and "Unzip with High-quality Sound".
The most difficult part is "Digital Compression Algorithm to minimize the Bandwidth", and "Unzip with High-quality Sound". To achieve this target can be "professional wireless".
So the NUX B-8 can run 1 MHz bandwidth with the shortest 2.5ms latency and bring back the unzipped sound with high quality. It also keeps stability with auto-hopping technology for long transmission distances. It may be the best 2.4GHz guitar wireless system in the market currently.
All the wireless systems will advise you to operate it far from the WiFi router at least 2 meters. Using the app can help you to detect the WiFi or RF interference source.
The pedal receiver usually puts the antenna on the top, as you can see B-8 has 2 antennas to enhance the signal. One thing you have to notice, please put the RX as high as possible to let the antenna higher above than other pedals without metal shielding.